BIOL 430N Data Visualization
February, 2025
What is (are) Research Data?
[R]esearch data represent any material derived from a source of
potential information, both measurable and abstract, gathered
for analysis or as part of developing findings or insights on a
subject.
- Unpublished RDM manuscript.
What are Possible Sources of Data?
people, films, photographs, recordings, artifacts, specimens, music
score sheets, art, an existing data set…
How are data classed?
Scales
Nominal (No Order)
Ordinal (Rank Odering)
Interval (Arbitrary Zero, Quantifiable Difference)
Ratio (Proportional)
Stevens, S. (1946). On the theory of scales of
Measurement. Science. 103 (2684).
Collection
Counted (Discrete, Observerd)
Measured (Continuous)
Set (Parameter, Categorical)
Reported (Survey, Nominal, Ordinal, Free Text)
Computational Representations
Numeric (integers, rationals)
Character (strings)
Boolean (true, false)…
Attributes
Dates, Currencies, Coordinates…
What is Data Visualization?
The abstraction of data, using shapes, colour, and
position.
Why do we Visualize Data?
Data visualization is the graphical display of abstract information
for two purposes: sense-making (also called data analysis) and
communication.
Stephen Few. Data
Visualization for Human Perception.
The greatest value of a picture is when it forces us to notice what
we never expected to see.
John W. Tukey (1977). “Exploratory Data
Analysis”
[T]he […] optic nerves are sending what we now know are 20 megabits a
second of information back to the brain […] [It] is being transformed
into information, into thinking, right as that step from the retina to
the brain. And the brain is really busy, and it likes to economize. And
so it’s quick to be active and jump to conclusions. So if you’re told
what to look for, you can’t see anything else.
Edward Tufte. Edward Tufte Wants You to
See Better. January 18, 2013. Talk of the Nation. https://www.npr.org/2013/01/18/169708761/edward-tufte-wants-you-to-see-better
There is no data that can be displayed in a pie chart, that cannot be
displayed better in some other type of chart.
- John W. Tukey. Attributed quote.
There is no such thing as information overload, just bad design. If
something is cluttered and/or confusing, fix your design.
- Edward Tufte. Attributed quote.
The London Tube Map
[Harry] Beck’s … brought [circuit layout] conventions to the Tube
map. That freed the map of any attachment to accurate representation of
geography and led to an abstracted visual … once you’re in the system,
what matters most is your logical relationship to the rest of the subway
system. Other maps that accurately show the geography can help you
figure out what to do on the surface, but while you’re underground the
only surface features that are accessible are the subway stations.
Noah Iliinsky (2010). On Beauty. In Beautiful
visualization: looking at data through the eyes of
experts.
“It may well be the best statistical graphic ever drawn.”
Tufte, E. (1983). The Visual Display of
Quantitative Information.
Figurative Map of the successive losses in men
of the French Army in the Russian campaign 1812–1813. Drawn up by M.
Minard, Inspector General of Bridges and Roads in retirement. Paris, 20
November 1869.
Source: https://en.wikipedia.org/wiki/File:Minard.png
Colour, Your Data, Your Audience
Medium (print, digital, distance)
Creating a Colour Scheme
| Hue |
Colour |
| Saturation |
Amount of Grey |
| Luminosity |
Amount of White and Black |
Try building palettes by adjusting a single element at a time.
